1. Field of the Invention
The present invention relates to a micro etching system using laser ablation, and more particularly to a micro etching system for making a micro line having a few hundred nanometers of line width by using laser ablation phenomenon and a near field optic-fiber probe.
2. Description of the Related Art
Generally, laser ablation means a phenomenon that a constituent atom is isolated from a crystal in a material by using high energy obtained by concentrating laser beam on a spot on the surface of the material.
In order to obtain laser ablation in a solid material, the laser beam of an ultraviolet (UV) wavelength is commonly used. The laser beam of the UV wavelength generated from a laser has enough energy to break off the binding energy of the crystal atoms when the laser beam is concentrated on a focus by using a conventional optical lens. The focus formed by the optical lens has an area of a few mm.sup.2, and the energy density for isolating a constituent atom from the surface of the target material reaches a range approximately from a few hundred milli Joule/cm.sup.2 to a few Joule/cm.sup.2.
Thus, it is impossible to use the conventional optical lens for making a line of a few ten nanometer line width, which is proposed by the present invention. The reason is that there is a physical restriction. Specifically, the focusing area of the lens focus cannot be smaller than the wavelength of the incident laser beam. In other words, the focusing area can not be of the size of a wavelength of 400 nm to 600 nm or less even though the beam is collected to the minimum size by using a conventional optical lens.